Illuminating glass structure.



PATENTED FEB. 17, 1903.

JNVENTOR,

15. L. O. WADSWORTH. ILLUMINATING GLASS STRUCTURE.

APPLIOATION FILED JULY 28, 1898.

K0 MODEL.

WITNESSES,-

A TTORNEYS.

-UNITED STATES PATENT OFFICE.

FRANK L. O. WADSWORTH, OF WILLIAMS BAY, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO PRESSED- PRISM PLATE GLASS COMPANY, A CORPORATION OF WEST VIRGINIA.

ILLU MINATING G LASS STRUCTU RE.

SPECIFICATION forming part of Letters Patent No. 720,987, dated February 17, 1903.

Application filed July 28, 1898. Serial No. 687,134. (No model.)

To all whmn it may concern: ments generally extend transversely across Be it known that I, FRANK L. O. VADS- the whole structure the curved surface as a WORTH, of Williams Bay, in the county of whole isa portion of the corresponding conic \Valworth and State of Wisconsin, have incylinder. The curvature is preferably, howvented a new and useful Improvement in ever, hyperbolic. It is not necessary that the Illuminating Glass Structures, of which the surface should be a continuously-curved one, following is a full, clear, and exact descripfor the desired result may be accomplished by tion, reference being had to the accompanymaking the surfaceaseries of flat stepsu uu", ing drawings, forming part of this specifica- Fig. 3, these successive flat faces forming tan- IO tion, in whichgent planes to the conic cylinder.

Figure 1 represents in cross-section a por The action of such an improved structure tion of the improved structure. Figs. 2 and upon rays of light falling upon it from difier- 3 are illustrated modifications, and Fig. 4 is ent directions from outside is illustrated in a. view showing an illuminating-plate of im- Fig. 1. It will be seen that the rays 1 1, 2 2,

15 proved construction. 3 3 3 are acted upon by the surfaces u and w The present application refers to that form in succession in sucha way as to emerge from of illuminating structure in which the pristhe inner side of the structure ,in the direcmatic elements are on the front or receiving tions 1 2 3 nearly parallel to each other. side of the structure and in which the light Rays, such as 4 4, coming from more nearly 20 is deflected into the space to be illuminated horizontal directions are refracted at the I by reflection from the lower faces to w of the faces it in such a way as in part to fall on the successive prism elements after first being faces wand from thence be reflected into the refracted at the series of receiving-faces u to room in the direction 4" 4 and in part to fall of the elements. 3 upon the inner plane side y of the structure 25 In the previous application Serial No. at less than the critical angle. This latter por- 687,133 I have shown the advantage of formtion of the rays is thereforetotally reflected at ing the refracting-faces u of prisms in such a the surface 'y, passes out toward the front way that the inner part of the face is more side of the structure in the directions l 49, nearly perpendicular to the plane of the and after a series of successive refractions at 30 structure than the outer part, and in another the faces to and w finally falls upon a face 10 application, Serial No. 687,132, I have shown at such an angle as to be totally reflected how by suitably curving faces corresponding into the room in the direction 4 4. to there fleeting-f aces w a larger proportion By making the retracting-surfaces to of the of the light coming from difierent directions prism elements curved, as above explained,

35 outside may be directed into the room in the I am enabled to collect from the outside of required direction than is possible when the the room or building in which the prisms are faces of the prism elements are plane. In the used rays coming from many difierent direcpresent application I secure this same result tions and to direct them all into the room in by curving the retracting-faces u u, leaving substantially the same main direction, secur- 0 the deflecting-faces 20 w flat. I have found ing thus a much greater illuminating effect at 0 that the form of curved faces which is most any desired point than is possible with prisefficient in securing this desired result is one matic elements allof whose surfaces are plain. which corresponds in cross-section with a The face y of the structure need not be curve 1; 1;", Fig. 2, of which the Vertex 0 is at plain, as shown in the drawings, but may be 45 a point in front of the illuminating structure ribbed or corrugated. The illuminating and of which the curvature continually instructure may be built up of separate prisms creases from the vertex u toward the back of suitably cemented or united, or it may be the structure. This curve is one of the conic constructed of a single integral piece, as sections-that is, either an elipse, a hypershown in the drawings. I

50 bola, or parabolaand as the prismatic ele- Within the scope of my invention as de- I00 fined in the claims many modifications may be made by those skilled in the art, since What I claim is 1. An illuminating structure having on the receiving side a series of prisms with light receiving and refracting surfaces curved to correspond to portions of conic cylinders; substantially as described.

2. An illuminating prism-plate having on the receiving side a series of prisms whose receiving and refracting faces at, u are curved to correspond in cross-section to a hyperbola whose vertexo lies on the front surface of the prism; substantially as described.

3. An illuminating prism-plate having a plain discharging-face, and on the receivingface a series of prisms whose receiving and refracting surfaces 10, u are curved to correspond to hyperbolic cylinders, and whose reflecting-surfaces w, w are plain and inclined at such an angle that the rays incident thereon are reflected in a direction substantially normal to the discharging-face of the prismplate; substantially as described.

4. An illuminating-prism having a cylindrical curved refracting-surface on the receiving side and a plain internally-reflecting surface wherefrom the rays are refracted in a direction substantially normal with the emergent face of the prism; substantially as described.

5. An illuminating-prism having on the receiving side surfaces u, w, the refractingsurface it being curved to correspond in cross-section with a portion of a conic curve, and the internally-reflecting surface w being plain; substantially as described.

6. An illuminating-prism having upon its receiving side curved refracting-surfaces and plain reflecting-surfaces also on the receiving side and joining the said curved surfaces, the latter curved in cross-section to correspond to a hyperbola Whose vertex is at a point in front of the illuminating structure with the curvature continually increasing from the said vertex toward the back of the prism.

In testimony whereof I havehereunto set my hand.

FRANK L. O. WADSWORTI-I. Witnesses:

C. BYRNES, G. I. HOLDSHIP. 

